For example, a technique described in Japanese Unexamined Patent Application Publication No. 2009-63043 (Patent Literature 1) is conventionally known as a technique relating to in-wheel motor drive devices. In an in-wheel motor drive device described in Patent Literature 1, a rotary pump is provided in a casing of the in-wheel motor drive device, and lubricant is forcibly circulated by the rotary pump to stably lubricate the entire region of a speed reduction portion. Moreover, a cooling water passage is provided in the casing to cool the in-wheel motor drive device.